Bioavailability and ecological risks of trace metals in bottom sediments from Doce river continental shelf before and after the biggest environmental disaster in Brazil: The collapse of the Fundão dam

Genomic features of a multidrug-resistant and mercury-tolerant environmental Escherichia coli recovered after a mining dam disaster in South America

“…of mining tailings were responsible for increasing the concentration of some metals. Copper, nickel, and zinc were higher in the reducible sediment fractions and associated with the tailings' original composition ( Aguiar et al, 2020 ). A recent study comparing trace metals in sediments before and after the disaster showed that the mud was the source of cadmium, and arsenic was present before the environmental disaster.…”

“…In 2015, Brazil experienced an environmental accident after an iron ore dam failure in the Doce River basin, Minas Gerais state ( Carmo et al, 2017 ), which raised the local environmental contamination and the bioavailability of heavy metals ( Aguiar et al, 2020 ). Although, the presence of antibiotic resistance genes in environments contaminated with heavy metal, as well as the role of heavy metals in co-selection and horizontal transfer of plasmid-mediated antibiotic resistance genes have been well documented ( Yang et al, 2017 ; Chen et al, 2019 ; Imran et al, 2019 ; Zhang et al, 2018 ), there is a lack of data about selection of critical priority pathogens and/or presence of resistant determinants in long-term metal contaminated areas affected by environmental accidents.…”

How does climate change affect small scale fisheries? A case study of the Lower Amazon in Brazil

“…In addition to climatic variables, fish fauna of alluvial plains of the Amazon basin are influenced by other aspects of the environment, such as water depth and transparency, and nutrients, which are natural secondary characteristics associated with variability in the fauna (Rodríguez & Lewis Jr., 1997; Tejerina‐Garro et al, 1998). Other anthropogenic effects include alterations in river flow and sediment deposition resulting from construction of hydroelectric dams (Doria et al, 2021; Latrubesse et al, 2017), pollution and alterations in water quality caused by mining and smelting operations (Aguiar et al, 2020; Magris et al, 2019), deforestation for extraction of lumber or cattle ranching (Vieira et al, 2008), and local fishery management practises that may interfere in maintenance of local fish stocks (Arantes et al, 2019).…”

The importance of organic carbon as a coadjutant in the transport of pollutants

“…The pollutants will be potentially trapped in the sediment, and in the case of remobilization, it will be an important source of further contamination (Lee et al 2017). Therefore, the identification and quantification of contaminants in the sediment and in the pore-water may provide the means to understand the flux of pollution, as well as information on potential threats to biota by toxic substances, in particular metals (Meili 1988;Krabbenhoft et al 1995;Barkay et al 1997;Aguiar et al 2020).…”

“…For instance, due to their higher specific surface area and capacity of cation exchange, fractions of sediment with smaller grain sizes assist a more intense carriage of pollutants. Another important factor is that fine-grained particulate matter is prone to resuspension and thus remains in the water column over longer periods of time, which allows them to interact with DOC (Zhang et al 2014;Buyang et al 2019;Aguiar et al 2020).…”